Apparatus for injecting a liquid into the vascular paths of a tree

ABSTRACT

A first piston 20 is cocked by applying pressure to a chamber 17 in the front end of a cylinder 10, which attendantly compresses a first spring 70. Upon subsequently releasing a trigger latch 82, the spring 70 drives an injection needle 31 carried by the rod 22 of the piston into a tree trunk. Pressure is next applied to a space 45 behind a second piston 40 slideable within the first piston skirt, which zero volumes a chamber 21 between the two pistons and compresses a second spring 71. The space 45 is then vented, whereupon the spring 71 separates the two piston heads to vacuum fill the reestablished chamber 21 with a vascular treatment liquid for trees. Finally, the space 45 is re-pressurized to force the liquid into the tree through the inserted needle.

BACKGROUND OF THE INVENTION

This invention concerns an apparatus for injecting a liquid into thevascular paths of a lignified plant.

Through direct injection into the stem of plants, in particular trees,growth regulators and protective agents are directly conveyed to trees.An important area of application of this technique of injection is alsothe prevention of disease or the combating of insects, which nourishthemselves on foliage or on wood grains. Insects can be combated just asare virus and fungus infections by means of this type of chemotherapy bythe application of antibiotics and/or systematic conveyance ofinsecticides. It is known that the combating of various insectepidemics, such as the psendophilus testacens in Ghana in March 1978,was successful in this way. Also, the spread of diseases can be broughtunder control.

In practice, the applied liquids were conveyed to the plants by gravitythrough discharge pipes of a container. Such apparatuses are notintended for poisonous substances, however, because the containerscannot be tightly closed. Highly effective modern insecticides arepoisonous to humans and must be kept in completely closed containers.

Insecticides with a phosphorous base are sufficiently effective thatonly quantities of 3 to 6 cm³ must be conveyed. Such substances are,however, poisonous to such an extent that instructions for theirhandling must be strictly followed.

DE-C 12 77 618 proposes to form the container out of two feather-shapedparts with closing bottoms able to conversely slide into each other,with their surface shells tightly superimposed on each other, to therebysolve the problem of tight containers. The liquid then flows by gravityout of the container into the trunk of the tree.

Another solution involves a container in which an additional space forthe production of a compressed gas is provided--see DE-C 12 40 325.

However, for the application of the medium, an injection needle mustfirst be inserted into the trunk up to those depths in which thevascular parts of the plants are found. In DE-C 15 82 802 an impactapparatus is utilized to drive the injection needle into the trunk, inorder to then be able to apply a container such as described above.Instead of driving an injection needle, DE-A 28 35 430 proposes to firstdrill holes in the trunk and then insert the nozzles into these holes.

In all of these known arrangements an injection needle or a nozzle isfirst inserted into the stem of the plant to be treated, and then theliquid in a desired quantity is introduced through the needle or thenozzle.

Up to now only one apparatus is known with which a liquid can beconveyed simultaneously with the formation of an access to the vascularparts--see U.S. Pat. No. 2,853,833. A cylindrical space with a valve isprovided in an axe body, is opened through a strike with the axe by atappet. A liquid is thereby conveyed, and departs through several canalsnear the cutting edge of the axe body. This is disadvantageous, however,because the plant is severely injured.

SUMMARY OF THE INVENTION

It is thus an object of this invention to provide an apparatus which canbe pushed directly into the trunk to a predetermined depth withoutadditional instruments for the insertion of the injection needle, andthereupon a desired quantity of a liquid can be driven in. Suchapparatus includes a spring driven needle, and a fluid chamber which isexpanded to draw in the treatment liquid and contracted to force it outthrough the needle and into the tree.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a part sectional view of an apparatus according to theinvention;

FIG. 2 is a top view of the apparatus, in part section, showing a devicefor releasing a piston in the apparatus;

FIG. 3 shows an anchor for mounting the apparatus of FIGS. 1 and 2, and

FIG. 4 is a diagram of a control device for applying the injectionneedle and for conveying liquid.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The injection device in accordance with FIGS. 1 and 2 consists of acasing 1 with an upper part 2 and an under part 3. The upper part 2mounts a carrying handle 4 and a rectangular compartment 5 for receivinga control apparatus 60 as shown in FIG. 4. The under part 3 houses allfunctional components.

The under part 3 has an inner cylindrical bore 10 closed on the left endby a base 11 on which a protective sheath 32 for the injection needle 31is mounted by a screw 34. The base 11 is centrally equipped with acylindrical connecting piece 13.

In cylinder bore 10 is found a first piston 20 which is fashioned with acentral hollow space 21 open at one end. The piston base 26 is integralwith an exterior piston rod 22, which extends into the connecting piece13 of the base 11. The piston rod 22 has a central bore 23 which forms aconduit for liquid from the space 21 to the injection needle 31 attachedto the piston rod. A non-return valve 24 in the bore 23 prevents thebackflow of the ejected liquid.

The hollow space 21 is also cylindrically fashioned, and receives asecond piston 40 connected to a tube-shaped piston rod 51 whichcentrally penetrates an end cover 12. A guide tube 50 surrounds the rod51, and on the piston side carries a base flange 55 held in a recess 15on the inside of the piston 20 by a snap ring 16.

A first spring 70 is disposed in the hollow space 75 between the guidetube 50 and the cylinder bore 10, and is supported at one end by thecover 12 and at the other end by a movable plate 72 bearing against thebottom of the first piston 20. A second spring 71 is disposed in thehollow space between the guide tube 50 and the rod 51 of the secondpiston 40. At one end this second spring is supported on a shoulder 73,and at the other end on an insert 57 held by a snap ring 56 on thepiston rod 51.

A first conduit 54 for pressurized fluid in the hollow space of thepiston rod 51 opens into the space 45 between second piston 40 and thebase flange 55.

In a connection element 46 rigidly connected with the piston rod 51, areinstalled two flexible tube couplings 47, 48. The coupling 47 suppliesfluid to the conduit 54.

A second conduit 53 in the piston rod 51 communicates through a passage41 and non-return valve 42 in the second piston 40 between the othercoupling 48 and the hollow space 21 in the first piston 20. Theinjection liquid is supplied through the coupling 48.

The control device 60, which is schematically shown in FIG. 4, has threeconnections A, B, and P. Connection A serves to convey pressurized fluidthrough the opening 14 in the cylinder base 11 to the space 17, andconnection B conveys the fluid through the hose coupling 47 to the space21.

The control device 60 includes four 3/2 distributing valves and one 2/2distributing valve. Two 3/2 distributing valves 61, 62 arehand-operated, and two 3/2 distributing valves 63, 64 are activated bythe pressurized fluid. The 2/2 distributing valve 65 is hand-operated.Accordingly, pressurized fluid from connection P can flow to connectionA through manual valve 62 to retract the needle and cock the piston 20.By operating valve 65, valve 64 is opened and thereafter held open bythe throttle 66 to close or "zero" the space 21 between the first andsecond pistons.

FIG. 2 shows a device for releasing the first piston 20. In an exteriorarea 81 of the lower casing part 3 is a firing lever 82 having a lockingcam 84 which engages a locking shoulder 25 of the first piston 20through a recess 85 in the cylinder wall 10. A safety catch or trigger83 supports the tensioned firing lever 82 in a known manner.

In operation, when the valve 62 is operated pressurized fluid flows outof connection A through the opening 14 in the cylinder base 11 and intothe space 17. The first piston 20 is thus driven to the right in FIG. 1together with the guide tube 50, the second piston 40, and the pistonrods 22 and 51 until the firing lever 82 snaps over the shoulder 25. Theapparatus is now cocked, with the spring 70 compressed. If the firinglever 82 is now released the spring 70 snaps the first piston 20together with its connected parts and in particular the needle 31 to theleft, until the impact dampers 27 strike against the cylinder base 11.Assuming that the sheath 32 and its anchor spike 33 were previouslyapplied against a tree trunk, the injection needle is consequentlydriven into the trunk.

By operating the valve 65 the second piston 40 is then driven to theleft in FIG. 1 to close the space 21 and compress spring 71. Throughsubsequent operation of valve 61 the P-B connection is interrupted tovent space 45 and the spring 71 forces the second piston 40 to theright, whereby through the coupling 48 injection liquid is drawn in byvacuum and fills the opened space 21.

By again operating the valve 65, the second piston 40 is driven to theleft in FIG. 1 and the fluid in the hollow space 21 is expelled into thetree trunk through the injection needle.

By means of an adjustable ring 74 clamped onto the piston rod 51, themovement of the rod can be limited so that if need be only a portion ofthe liquid is ejected from the hollow space 21.

To bring the impact of the released spring 70 with full effect onto theinjection needle, a backing or reaction support is provided inaccordance with FIG. 3. This support 90 has a base plate 91 with anchorspikes 92 and an anchor bar 93, which by means of two perpendicularpivot joints 95, 96 can be brought into any desired position, includinga vertical one as shown. By means of an adjustably positioned gripper94, a curved support bar 80 attached behind the casing 1 may be set tothe correct working height.

As seen in FIG. 2, springs 86 disposed between the opposite exteriorareas 81 and the lower casing part 3 enable a limited longitudinaldisplacement so that, if necessary, the length of the apparatus betweena tree trunk and the support 90 may be shortened or compressed.

The injection needle 31 may have an elliptical cross-section which ifaligned with the tree grain will make at the most a trivial wound ascontrasted with the prior art boring or axe cut, which can in many casesbe more damaging than the injection can be of use.

What is claimed is:
 1. An apparatus for injecting a prescribed quantityof a liquid into a vascular path of a lignified plant, comprising:(a) ahollow cylinder (10) closed by a centrally apertured base (11) at oneend and by a centrally apertured cover (12) at another, opposite end,(b) a first piston (20) slidably disposed in the cylinder and having ahollow skirt defining a liquid receiving first chamber (21) and a firsthollow rod (22) extending from a head of the piston out through the baseaperture and communicating with the chamber through a delivery passagein the head, (c) an injection needle (31) mounted on the outwardlyextending end of the rod, (d) a second piston (40) slidably disposedwithin the skirt of the first piston and defining one end of thechamber, the movement of the second piston within the skirt of the firstpiston thus varying the volume of the chamber, (e) a supply passage (41)defined within the second piston for delivering liquid to the chamber,and (f) means (60, FIG. 4) for controlling the movement of both pistonsto:(1) drive the tip of the needle into a vascular path of a lignifiedplant, and (2) pump liquid into the plant.
 2. An apparatus according toclaim 1, wherein:(a) a flanged (55) cylindrical sleeve (50) is rigidlymounted to the skirt of the first piston and extends out through thecylinder cover aperture, the sleeve flange and the second pistondefining a second chamber (45) therebetween, (b) a second hollow rod(51) is integral with the second piston and extends out through thesleeve, (c) a first conduit (53) is provided within the second rodcommunicating with the supply passage of the second piston, and (d) asecond conduit (54) is provided within the second rod communicating withthe second chamber for supplying pressurized fluid thereto and forventing fluid therefrom, and further comprising: (e) a first helicalspring (70) surrounding the sleeve and disposed between the skirt of thefirst piston and the cylinder cover for driving the first piston toinsert the needle, and (f) a second helical spring (71) surrounding thesecond rod and disposed between the sleeve flange and the outwardlyextending end of the second rod for decreasing the volume of the firstchamber to pump the liquid.
 3. An apparatus according to claim 2,wherein a pair of non-return valves (24, 42) are individually disposedin the delivery and supply passages of the first and second pistons. 4.An apparatus according to claim 3, wherein passage means (14) areprovided in the cylinder proximate the base thereof for supplyingpressurized fluid to a third chamber (17) defined between the firstpiston head and said base to compressively cock the first springpursuant to driving the needle tip.
 5. An apparatus according to claim4, wherein the controlling means comprises a plurality of manually andspring controlled valves (61-65) for selectively pressurizing the secondand third chambers.
 6. An apparatus according to claim 5, wherein:(a) aU-shaped support bar (80, 81) surrounds the cylinder and is springmounted (86) to the apparatus proximate the cylinder base, and (b)anchor means (90) are coupled to a rear portion of the support barremote from the cylinder base for supporting and bracing the apparatusagainst a plant to be treated.
 7. An apparatus according to claim 6,wherein trigger release means (82) are mounted in the support bar forengaging a shoulder (25) of the first piston to latch the cocked firstspring.